Update coders with error return values

AApparently the message does not use it

encoding/ascii.go

@@ -0,0 +1,14 @@
+package encoding
+
+import "bytes"
+
+type ASCIICoder struct{}
+
+func (c *ASCIICoder) Encode(s string, buf *bytes.Buffer) error {
+	buf.WriteString(s)
+	return nil
+}
+
+func (c *ASCIICoder) Decode(buf *bytes.Buffer) (string, error) {
+	return buf.String(), nil
+}

encoding/ascii_test.go

@@ -0,0 +1,74 @@
+package encoding
+
+import (
+	"bytes"
+	"testing"
+)
+
+func TestASCIIEncodeSimpleASCIIString(t *testing.T) {
+	coder := &ASCIICoder{}
+	var buf bytes.Buffer
+	input := "Hello, World!"
+
+	expected := []byte{72, 101, 108, 108, 111, 44, 32, 87, 111, 114, 108, 100, 33}
+	err := coder.Encode(input, &buf)
+
+	if err != nil {
+		t.Errorf("Expected no error, but got %v", err)
+	}
+
+	if !bytes.Equal(buf.Bytes(), expected) {
+		t.Errorf("Expected %v, but got %v", expected, buf.Bytes())
+	}
+}
+
+func TestASCIIDecodeSimpleASCIIString(t *testing.T) {
+	coder := &ASCIICoder{}
+	var buf bytes.Buffer
+	input := []byte{72, 101, 108, 108, 111, 44, 32, 87, 111, 114, 108, 100, 33}
+
+	expected := "Hello, World!"
+	buf.Write(input)
+	output, err := coder.Decode(&buf)
+
+	if err != nil {
+		t.Errorf("Expected no error, but got %v", err)
+	}
+
+	if output != expected {
+		t.Errorf("Expected %v, but got %v", expected, output)
+	}
+}
+
+func TestASCIIEncodeEmptyString(t *testing.T) {
+	coder := &ASCIICoder{}
+	var buf bytes.Buffer
+	input := ""
+
+	expected := []byte{}
+	err := coder.Encode(input, &buf)
+
+	if err != nil {
+		t.Errorf("Expected no error, but got %v", err)
+	}
+
+	if !bytes.Equal(buf.Bytes(), expected) {
+		t.Errorf("Expected %v, but got %v", expected, buf.Bytes())
+	}
+}
+
+func TestASCIIDecodeEmptyString(t *testing.T) {
+	coder := &ASCIICoder{}
+	buf := bytes.NewBuffer([]byte{})
+
+	expected := ""
+	output, err := coder.Decode(buf)
+
+	if err != nil {
+		t.Errorf("Expected no error, but got %v", err)
+	}
+
+	if output != expected {
+		t.Errorf("Expected %v, but got %v", expected, output)
+	}
+}

encoding/charset.json

@@ -0,0 +1,5 @@
+{
+	"ucs2": {
+		"link": "http://www.columbia.edu/kermit/ucs2.html"
+	}
+}

encoding/coder.go

@@ -0,0 +1,8 @@
+package encoding
+
+import "bytes"
+
+type Coder interface {
+	Encode(s string, buf *bytes.Buffer) error
+	Decode(buf *bytes.Buffer) (string, error)
+}

encoding/gsm7.go

@@ -0,0 +1,18 @@
+package encoding
+
+import (
+	"bytes"
+	"log"
+)
+
+type GSM7Coder struct{}
+
+func (c *GSM7Coder) Encode(s string, buf *bytes.Buffer) {
+	utf8 := []byte(s)
+	log.Println(utf8)
+	buf.Write(utf8)
+}
+
+func (c *GSM7Coder) Decode(buf *bytes.Buffer) string {
+	return buf.String()
+}

encoding/gsm7_test.go

@@ -0,0 +1,58 @@
+package encoding
+
+import (
+	"bytes"
+	"testing"
+)
+
+func TestGSM7EncodeSimpleASCIIString(t *testing.T) {
+	coder := &GSM7Coder{}
+	var buf bytes.Buffer
+	input := "Sunshine"
+
+	expected := []byte{0b11010011, 0b10111001, 0b10111011, 0b10001110, 0b01001110, 0b10111011, 0b11001011}
+	coder.Encode(input, &buf)
+
+	if !bytes.Equal(buf.Bytes(), expected) {
+		t.Errorf("Expected %v, but got %v", expected, buf.Bytes())
+	}
+}
+
+func TestGSM7DecodeSimpleASCIIString(t *testing.T) {
+	coder := &GSM7Coder{}
+	var buf bytes.Buffer
+	input := []byte{0b11010011, 0b10111001, 0b10111011, 0b10001110, 0b01001110, 0b10111011, 0b11001011}
+
+	expected := "Sunshine"
+	buf.Write(input)
+	output := coder.Decode(&buf)
+
+	if output != expected {
+		t.Errorf("Expected %v, but got %v", expected, output)
+	}
+}
+
+func TestGSM7EncodeEmptyString(t *testing.T) {
+	coder := &GSM7Coder{}
+	var buf bytes.Buffer
+	input := ""
+
+	expected := []byte{}
+	coder.Encode(input, &buf)
+
+	if !bytes.Equal(buf.Bytes(), expected) {
+		t.Errorf("Expected %v, but got %v", expected, buf.Bytes())
+	}
+}
+
+func TestGSM7DecodeEmptyString(t *testing.T) {
+	coder := &GSM7Coder{}
+	buf := bytes.NewBuffer([]byte{})
+
+	expected := ""
+	output := coder.Decode(buf)
+
+	if output != expected {
+		t.Errorf("Expected %v, but got %v", expected, output)
+	}
+}

encoding/ucs2.go

@@ -0,0 +1,13 @@
+package encoding
+
+import "bytes"
+
+type UCS2Coder struct{}
+
+func (c *UCS2Coder) Encode(s string, buf *bytes.Buffer) {
+	panic("UCS2 not implemented yet")
+}
+
+func (c *UCS2Coder) Decode(buf *bytes.Buffer) string {
+	panic("UCS2 not implemented yet")
+}

go.mod

@@ -2,4 +2,7 @@ module smpptester
 
 go 1.22.4
 
-require github.com/yuin/gopher-lua v1.1.1
+require (
+	github.com/warthog618/sms v0.3.0
+	github.com/yuin/gopher-lua v1.1.1
+)

go.sum

@@ -1,2 +1,16 @@
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
+github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
+github.com/niemeyer/pretty v0.0.0-20200227124842-a10e7caefd8e/go.mod h1:zD1mROLANZcx1PVRCS0qkT7pwLkGfwJo4zjcN/Tysno=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
+github.com/warthog618/sms v0.3.0 h1:LYAb5ngmu2qjNExgji3B7xi2tIZ9+DsuE9pC5xs4wwc=
+github.com/warthog618/sms v0.3.0/go.mod h1:+bYZGeBxu003sxD5xhzsrIPBAjPBzTABsRTwSpd7ld4=
 github.com/yuin/gopher-lua v1.1.1 h1:kYKnWBjvbNP4XLT3+bPEwAXJx262OhaHDWDVOPjL46M=
 github.com/yuin/gopher-lua v1.1.1/go.mod h1:GBR0iDaNXjAgGg9zfCvksxSRnQx76gclCIb7kdAd1Pw=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/check.v1 v1.0.0-20200227125254-8fa46927fb4f/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
+gopkg.in/yaml.v2 v2.2.8/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=

main.go

@@ -136,6 +136,7 @@ func main() {
 	// 		go handleConnection(conn)
 	// 	}
 	// }()
+	log.Println(createSubmitSMPDU())
 
 	wg := &sync.WaitGroup{}
 	wg.Add(1)

pdu/bind.go

@@ -2,19 +2,19 @@ package pdu
 
 type (
 	BIND struct {
-		header            PDU_HEADER
+		header            *PDU_HEADER
 		system_id         string
 		password          string
 		system_type       string
-		interface_version uint8
+		interface_version byte
-		addr_ton          uint8
+		addr_ton          byte
-		addr_npi          uint8
+		addr_npi          byte
 		address_range     string
 	}
 	BIND_RESP struct {
-		header               PDU_HEADER
+		header               *PDU_HEADER
 		system_id            string
-		sc_interface_version uint8
+		sc_interface_version byte
 	}
 	BIND_RECVEIVER struct {
 		BIND
@@ -36,9 +36,9 @@ type (
 	}
 
 	UNBIND struct {
-		PDU_HEADER
+		header *PDU_HEADER
 	}
 	UNBIND_RESP struct {
-		PDU_HEADER
+		header *PDU_HEADER
 	}
 )

pdu/bufpool.go

@@ -1,21 +1,30 @@
 package pdu
 
 import (
+	"bytes"
+	"log"
 	"sync"
 )
 
 type BufferPoolManager struct {
-	pools map[uint]*sync.Pool
+	pools map[int]*sync.Pool
 	mu    sync.RWMutex
+	debug bool
+}
+
+func (bpm *BufferPoolManager) logf(format string, args ...interface{}) {
+	if bpm.debug {
+		log.Printf(format, args...)
+	}
 }
 
 func NewBufferPoolManager() *BufferPoolManager {
 	return &BufferPoolManager{
-		pools: make(map[uint]*sync.Pool),
+		pools: make(map[int]*sync.Pool),
 	}
 }
 
-func (bpm *BufferPoolManager) Get(size uint) *[]uint8 {
+func (bpm *BufferPoolManager) Get(size int) *bytes.Buffer {
 	bpm.mu.RLock()
 	pool, exists := bpm.pools[size]
 	bpm.mu.RUnlock()
@@ -25,10 +34,13 @@ func (bpm *BufferPoolManager) Get(size uint) *[]uint8 {
 		// Double-check if another goroutine added the pool while we were waiting
 		pool, exists = bpm.pools[size]
 		if !exists {
+			bpm.logf("Creating new pool for size %d\n", size)
 			pool = &sync.Pool{
 				New: func() interface{} {
-					buf := make([]uint8, size)
+					bpm.logf("Creating new buffer of size %d\n", size)
-					return &buf
+					buf := bytes.NewBuffer(make([]byte, size))
+					buf.Reset()
+					return buf
 				},
 			}
 			bpm.pools[size] = pool
@@ -36,23 +48,23 @@ func (bpm *BufferPoolManager) Get(size uint) *[]uint8 {
 		bpm.mu.Unlock()
 	}
 
-	return pool.Get().(*[]uint8)
+	buf := pool.Get().(*bytes.Buffer)
+	bpm.logf("Returning buffer of size %d: %p\n", buf.Cap(), buf)
+	return buf
 }
 
-func (bpm *BufferPoolManager) Put(buf *[]uint8) {
+func (bpm *BufferPoolManager) Put(buf *bytes.Buffer) {
-	size := uint(len(*buf))
+	size := buf.Cap()
 	bpm.mu.RLock()
 	pool, exists := bpm.pools[size]
 	bpm.mu.RUnlock()
 
 	if !exists {
+		bpm.logf("Cannot return %p, No pool for size %d\n", buf, size)
 		return
 	}
 
-	// Clear buffer
+	buf.Reset()
-	for i := range *buf {
-		(*buf)[i] = 0
-	}
-
 	pool.Put(buf)
+	bpm.logf("Returned buffer of size %d: %p\n", size, buf)
 }

pdu/bufpool_test.go

@@ -10,14 +10,14 @@ func TestRetrieveBufferOfRequestedSize(t *testing.T) {
 	bpm := NewBufferPoolManager()
 
 	size := 1024
-	buffer := bpm.Get(uint(size))
+	buffer := bpm.Get(size)
 
 	if buffer == nil {
 		t.Fatalf("Expected buffer, got nil")
 	}
 
-	if len(*buffer) != size {
+	if buffer.Cap() != size {
-		t.Errorf("Expected buffer size %d, got %d", size, len(*buffer))
+		t.Errorf("Expected buffer size %d, got %d", size, buffer.Cap())
 	}
 }
 
@@ -25,14 +25,14 @@ func TestRequestBufferSizeZero(t *testing.T) {
 	bpm := NewBufferPoolManager()
 
 	size := 0
-	buffer := bpm.Get(uint(size))
+	buffer := bpm.Get(size)
 
 	if buffer == nil {
 		t.Fatalf("Expected buffer, got nil")
 	}
 
-	if len(*buffer) != size {
+	if buffer.Cap() != size {
-		t.Errorf("Expected buffer size %d, got %d", size, len(*buffer))
+		t.Errorf("Expected buffer size %d, got %d", size, buffer.Cap())
 	}
 }
 
@@ -47,12 +47,12 @@ func TestConcurrentAccessToBufferPool(t *testing.T) {
 		wg.Add(1)
 		go func() {
 			defer wg.Done()
-			buffer := bpm.Get(uint(size))
+			buffer := bpm.Get(size)
 			if buffer == nil {
 				t.Errorf("Expected buffer, got nil")
 			}
-			if len(*buffer) != size {
+			if buffer.Cap() != size {
-				t.Errorf("Expected buffer size %d, got %d", size, len(*buffer))
+				t.Errorf("Expected buffer size %d, got %d", size, buffer.Cap())
 			}
 		}()
 	}
@@ -64,14 +64,14 @@ func TestGetBufferLockUnlock(t *testing.T) {
 	bpm := NewBufferPoolManager()
 
 	size := 1024
-	buffer := bpm.Get(uint(size))
+	buffer := bpm.Get(size)
 
 	if buffer == nil {
 		t.Fatalf("Expected buffer, got nil")
 	}
 
-	if len(*buffer) != size {
+	if buffer.Cap() != size {
-		t.Errorf("Expected buffer size %d, got %d", size, len(*buffer))
+		t.Errorf("Expected buffer size %d, got %d", size, buffer.Cap())
 	}
 }
 
@@ -79,14 +79,14 @@ func TestVerifyPoolCreationForNewSizes(t *testing.T) {
 	bpm := NewBufferPoolManager()
 
 	size := 512
-	buffer := bpm.Get(uint(size))
+	buffer := bpm.Get(size)
 
 	if buffer == nil {
 		t.Fatalf("Expected buffer, got nil")
 	}
 
-	if len(*buffer) != size {
+	if buffer.Cap() != size {
-		t.Errorf("Expected buffer size %d, got %d", size, len(*buffer))
+		t.Errorf("Expected buffer size %d, got %d", size, buffer.Cap())
 	}
 }
 
@@ -94,14 +94,14 @@ func TestBufferPoolManagerGetBuffer(t *testing.T) {
 	bpm := NewBufferPoolManager()
 
 	size := 1024
-	buffer := bpm.Get(uint(size))
+	buffer := bpm.Get(size)
 
 	if buffer == nil {
 		t.Fatalf("Expected buffer, got nil")
 	}
 
-	if len(*buffer) != size {
+	if buffer.Cap() != size {
-		t.Errorf("Expected buffer size %d, got %d", size, len(*buffer))
+		t.Errorf("Expected buffer size %d, got %d", size, buffer.Cap())
 	}
 }
 
@@ -110,14 +110,14 @@ func TestGetBufferWithMultipleSizes(t *testing.T) {
 
 	sizes := []int{512, 1024, 2048}
 	for _, size := range sizes {
-		buffer := bpm.Get(uint(size))
+		buffer := bpm.Get(size)
 
 		if buffer == nil {
 			t.Fatalf("Expected buffer for size %d, got nil", size)
 		}
 
-		if len(*buffer) != size {
+		if buffer.Cap() != size {
-			t.Errorf("Expected buffer size %d, got %d", size, len(*buffer))
+			t.Errorf("Expected buffer size %d, got %d", size, buffer.Cap())
 		}
 	}
 }
@@ -125,7 +125,7 @@ func TestGetBufferWithMultipleSizes(t *testing.T) {
 func TestGetBufferIsAlwaysZero(t *testing.T) {
 	bpm := NewBufferPoolManager()
 
-	var size uint = 1024 * 64
+	size := 1024 * 64
 	for i := 0; i < 1000; i++ {
 		buffer := bpm.Get(size)
 
@@ -133,11 +133,11 @@ func TestGetBufferIsAlwaysZero(t *testing.T) {
 			t.Fatalf("Expected buffer for size %d, got nil", size)
 		}
 
-		if uint(len(*buffer)) != size {
+		if buffer.Cap() != size {
-			t.Errorf("Expected buffer size %d, got %d", size, len(*buffer))
+			t.Errorf("Expected buffer size %d, got %d", size, buffer.Cap())
 		}
 
-		for _, b := range *buffer {
+		for _, b := range buffer.Bytes() {
 			if b != 0 {
 				t.Errorf("Expected buffer to be zero, got %d", b)
 			}
@@ -147,9 +147,26 @@ func TestGetBufferIsAlwaysZero(t *testing.T) {
 	}
 }
 
+func TestPoolReusesBuffers(t *testing.T) {
+	bpm := NewBufferPoolManager()
+
+	size := 1024
+	buffer := bpm.Get(size)
+	initialPtr := buffer
+	bpm.Put(buffer)
+	for i := 0; i < 1000; i++ {
+		buffer = bpm.Get(size)
+		if buffer != initialPtr {
+			t.Errorf("Expected initial buffer (%p) to be reused, got %p", initialPtr, buffer)
+		}
+		bpm.Put(buffer)
+	}
+}
+
+// region benchmark
 func BenchmarkBufferPoolManager(b *testing.B) {
 	bpm := NewBufferPoolManager()
-	bufSize := uint(128 * 1024) // a PDU should not be larger than this... Even this is way too large
+	bufSize := 128 * 1024 // a PDU should not be larger than this... Even this is way too large
 
 	b.ResetTimer()
 
@@ -163,7 +180,7 @@ func BenchmarkBufferPoolManager(b *testing.B) {
 
 func BenchmarkBufferPoolManager_Concurrent(b *testing.B) {
 	bpm := NewBufferPoolManager()
-	bufSize := uint(128 * 1024) // a PDU should not be larger than this... Even this is vway too large
+	bufSize := 128 * 1024 // a PDU should not be larger than this... Even this is way too large
 
 	b.ResetTimer()
 
@@ -186,17 +203,17 @@ func BenchmarkBufferPoolManager_Concurrent(b *testing.B) {
 
 func BenchmarkBufferPoolManager_Memory(b *testing.B) {
 	bpm := NewBufferPoolManager()
-	bufSize := uint(128 * 1024) // a PDU should not be larger than this... Even this is vway too large
+	bufSize := 128 * 1024 // a PDU should not be larger than this... Even this is way too large
 	b.ResetTimer()
 
-	var i uint8
+	var i byte
 	buf := bpm.Get(bufSize)
 	b.StopTimer()
 
 	// Simulate some work
 	time.Sleep(10 * time.Millisecond)
-	for k := range *buf {
+	for range buf.Bytes() {
-		(*buf)[k] = i % 255
+		buf.WriteByte(i % 255)
 	}
 
 	b.StartTimer()

pdu/cancel.go

@@ -2,17 +2,17 @@ package pdu
 
 type (
 	CANCEL_SM struct {
-		header           PDU_HEADER
+		header           *PDU_HEADER
 		service_type     string
 		message_id       string
-		source_addr_ton  uint8
+		source_addr_ton  byte
-		source_addr_npi  uint8
+		source_addr_npi  byte
 		source_addr      string
-		dest_addr_ton    uint8
+		dest_addr_ton    byte
-		dest_addr_npi    uint8
+		dest_addr_npi    byte
 		destination_addr string
 	}
 	CANCEL_SM_RESP struct {
-		header PDU_HEADER
+		header *PDU_HEADER
 	}
 )

pdu/deliver.go

@@ -2,11 +2,11 @@ package pdu
 
 type (
 	DELIVER_SM struct {
-		header PDU_HEADER
+		header *PDU_HEADER
 		SUBMIT_SM
 	}
 	DELIVER_SM_RESP struct {
-		header PDU_HEADER
+		header *PDU_HEADER
 		SUBMIT_SM_RESP
 	}
 )

pdu/enquire.go

@@ -2,9 +2,9 @@ package pdu
 
 type (
 	ENQUIRE_LINK struct {
-		header PDU_HEADER
+		header *PDU_HEADER
 	}
 	ENQUIRE_LINK_RESP struct {
-		header PDU_HEADER
+		header *PDU_HEADER
 	}
 )

pdu/global.go

@@ -1,3 +1,5 @@
 package pdu
 
 var ByteBufferPool = NewBufferPoolManager()
+const NULL = byte(0x00)
+var NULL_ARR = []byte{NULL}

pdu/pdu.go

@@ -1,17 +1,18 @@
 package pdu
 
 import (
+	"bytes"
 	"encoding/binary"
 	"fmt"
 )
 
 type (
 	PDU interface {
-		EncodeInto(*[]uint8)
+		Encode(*bytes.Buffer) error
-		Encode() []uint8
+		Decode(*bytes.Buffer) error
-		Decode([]uint8)
 		// Size in bytes
-		Size() uint32
+		Size() int
+		UpdateSize()
 	}
 
 	PDU_HEADER struct {
@@ -22,7 +23,7 @@ type (
 	}
 
 	GENERIC_NACK struct {
-		header PDU_HEADER
+		header *PDU_HEADER
 	}
 )
 
@@ -57,41 +58,29 @@ type (
 // What are the other 0s?
 // Don't know
 
-func (p *PDU_HEADER) Encode() (*[]uint8, error) {
+func (p *PDU_HEADER) Encode(buf *bytes.Buffer) error {
-	buf := ByteBufferPool.Get(uint(p.Size()))
-	err := p.EncodeInto(buf)
-	return buf, err
-}
-func (p *PDU_HEADER) EncodeInto(buf *[]uint8) error {
 	if buf == nil {
-		return fmt.Errorf("cannot encode PDU_HEADER, buffer is nil")
+		return fmt.Errorf("cannot encode into nil buffer")
 	}
-	if len(*buf) < 16 {
+	binary.Write(buf, binary.BigEndian, p.command_length)
-		return fmt.Errorf("cannot encode PDU_HEADER, buffer too small (%d, required 16)", len(*buf))
+	binary.Write(buf, binary.BigEndian, p.command_id)
-	}
+	binary.Write(buf, binary.BigEndian, p.command_status)
-	bufVal := *buf
+	binary.Write(buf, binary.BigEndian, p.sequence_number)
-	binary.BigEndian.PutUint32(bufVal[0:4], p.command_length)
-	binary.BigEndian.PutUint32(bufVal[4:8], p.command_id)
-	binary.BigEndian.PutUint32(bufVal[8:12], p.command_status)
-	binary.BigEndian.PutUint32(bufVal[12:16], p.sequence_number)
 	return nil
 }
-func (p *PDU_HEADER) Decode(data []uint8) error {
+func (p *PDU_HEADER) Decode(buf *bytes.Buffer) error {
-	if len(data) >= 4 {
+	if buf == nil {
-		p.command_length = binary.BigEndian.Uint32(data[0:4])
+		return fmt.Errorf("cannot decode nil buffer")
-	}
-	if len(data) >= 8 {
-		p.command_id = binary.BigEndian.Uint32(data[4:8])
-	}
-	if len(data) >= 12 {
-		p.command_status = binary.BigEndian.Uint32(data[8:12])
-
-	}
-	if len(data) >= 16 {
-		p.sequence_number = binary.BigEndian.Uint32(data[12:16])
 	}
+	binary.Read(buf, binary.BigEndian, &p.command_length)
+	binary.Read(buf, binary.BigEndian, &p.command_id)
+	binary.Read(buf, binary.BigEndian, &p.command_status)
+	binary.Read(buf, binary.BigEndian, &p.sequence_number)
 	return nil
 }
-func (p *PDU_HEADER) Size() uint32 {
+func (p *PDU_HEADER) Size() int {
 	return 16
 }
+func (p *PDU_HEADER) UpdateSize() {
+	p.command_length = uint32(p.Size())
+}

pdu/pdu_test.go

@@ -1,6 +1,7 @@
 package pdu
 
 import (
+	"bytes"
 	"encoding/binary"
 	"math"
 	"sync"
@@ -15,13 +16,15 @@ func TestEncodeReturnsByteSliceOfLength16(t *testing.T) {
 		command_status:  1,
 		sequence_number: 1,
 	}
-	result, err := p.Encode()
+	buf := bytes.NewBuffer(make([]byte, 16))
+	buf.Reset()
+	err := p.Encode(buf)
 
 	if err != nil {
 		t.Errorf("Expected no error, got %v", err)
 	}
-	if len(*result) != 16 {
+	if buf.Cap() != 16 {
-		t.Errorf("Expected byte slice of length 16, got %d", len(*result))
+		t.Errorf("Expected byte slice of length 16, got %d", buf.Cap())
 	}
 }
 
@@ -32,15 +35,17 @@ func TestEncodeHandlesZeroValues(t *testing.T) {
 		command_status:  0,
 		sequence_number: 0,
 	}
-	result, err := p.Encode()
+	buf := bytes.NewBuffer(make([]byte, 16))
+	buf.Reset()
+	err := p.Encode(buf)
 
 	if err != nil {
 		t.Errorf("Expected no error, got %v", err)
 	}
-	expected := make([]uint8, 16)
+	expected := make([]byte, 16)
-	for i, v := range *result {
+	for i, v := range buf.Bytes() {
 		if v != expected[i] {
-			t.Errorf("Expected byte slice with zero values, got %v", *result)
+			t.Errorf("Expected byte slice with zero values, got %v", buf.Bytes())
 			break
 		}
 	}
@@ -53,16 +58,18 @@ func TestEncodeEncodesProperly(t *testing.T) {
 		command_status:  3,
 		sequence_number: 4,
 	}
-	result, err := p.Encode()
+	buf := bytes.NewBuffer(make([]byte, 16))
+	buf.Reset()
+	err := p.Encode(buf)
 
 	if err != nil {
 		t.Errorf("Expected no error, got %v", err)
 	}
 
-	expected := []uint8{0, 0, 0, 1, 0, 0, 0, 2, 0, 0, 0, 3, 0, 0, 0, 4}
+	expected := []byte{0, 0, 0, 1, 0, 0, 0, 2, 0, 0, 0, 3, 0, 0, 0, 4}
-	for i, v := range *result {
+	for i, v := range buf.Bytes() {
 		if v != expected[i] {
-			t.Errorf("Expected byte slice with values %v, got %v", expected, *result)
+			t.Errorf("Expected byte slice with values %v, got %v", expected, buf.Bytes())
 			break
 		}
 	}
@@ -75,16 +82,18 @@ func TestEncodeEncodesProperlyComplex(t *testing.T) {
 		command_status:  35634264,
 		sequence_number: 476543523,
 	}
-	result, err := p.Encode()
+	buf := bytes.NewBuffer(make([]byte, 16))
+	buf.Reset()
+	err := p.Encode(buf)
 
 	if err != nil {
 		t.Errorf("Expected no error, got %v", err)
 	}
 
-	expected := []uint8{0, 204, 224, 36, 0, 3, 225, 144, 2, 31, 188, 88, 28, 103, 122, 35}
+	expected := []byte{0, 204, 224, 36, 0, 3, 225, 144, 2, 31, 188, 88, 28, 103, 122, 35}
-	for i, v := range *result {
+	for i, v := range buf.Bytes() {
 		if v != expected[i] {
-			t.Errorf("Expected byte slice with values %v, got %v", expected, *result)
+			t.Errorf("Expected byte slice with values %v, got %v", expected, buf.Bytes())
 			break
 		}
 	}
@@ -97,54 +106,26 @@ func TestEncodeIntoCorrectlyEncodesFields(t *testing.T) {
 		command_status:  0,
 		sequence_number: 12345,
 	}
-	buf := make([]uint8, 16)
+	buf := bytes.NewBuffer(make([]byte, 16))
-	err := p.EncodeInto(&buf)
+	buf.Reset()
+	err := p.Encode(buf)
 
 	if err != nil {
 		t.Errorf("Expected no error, got %v", err)
 	}
 
-	if binary.BigEndian.Uint32(buf[0:4]) != p.command_length {
+	innerbuf := buf.Bytes()
-		t.Errorf("Expected command_length %d, got %d", p.command_length, binary.BigEndian.Uint32(buf[0:4]))
+	if binary.BigEndian.Uint32(innerbuf[0:4]) != p.command_length {
+		t.Errorf("Expected command_length %d, got %d", p.command_length, binary.BigEndian.Uint32(innerbuf[0:4]))
 	}
-	if binary.BigEndian.Uint32(buf[4:8]) != p.command_id {
+	if binary.BigEndian.Uint32(innerbuf[4:8]) != p.command_id {
-		t.Errorf("Expected command_id %d, got %d", p.command_id, binary.BigEndian.Uint32(buf[4:8]))
+		t.Errorf("Expected command_id %d, got %d", p.command_id, binary.BigEndian.Uint32(innerbuf[4:8]))
 	}
-	if binary.BigEndian.Uint32(buf[8:12]) != p.command_status {
+	if binary.BigEndian.Uint32(innerbuf[8:12]) != p.command_status {
-		t.Errorf("Expected command_status %d, got %d", p.command_status, binary.BigEndian.Uint32(buf[8:12]))
+		t.Errorf("Expected command_status %d, got %d", p.command_status, binary.BigEndian.Uint32(innerbuf[8:12]))
 	}
-	if binary.BigEndian.Uint32(buf[12:16]) != p.sequence_number {
+	if binary.BigEndian.Uint32(innerbuf[12:16]) != p.sequence_number {
-		t.Errorf("Expected sequence_number %d, got %d", p.sequence_number, binary.BigEndian.Uint32(buf[12:16]))
+		t.Errorf("Expected sequence_number %d, got %d", p.sequence_number, binary.BigEndian.Uint32(innerbuf[12:16]))
-	}
-}
-
-func TestEncodeIntoHandlesNilBuffer(t *testing.T) {
-	p := &PDU_HEADER{
-		command_length:  16,
-		command_id:      1,
-		command_status:  0,
-		sequence_number: 12345,
-	}
-	var buf *[]uint8 = nil
-
-	err := p.EncodeInto(buf)
-	if err == nil {
-		t.Errorf("Expected error when buffer is nil")
-	}
-}
-
-func TestEncodeIntoHandlesSmallerBuffer(t *testing.T) {
-	p := &PDU_HEADER{
-		command_length:  16,
-		command_id:      1,
-		command_status:  0,
-		sequence_number: 12345,
-	}
-	buf := make([]uint8, 12) // smaller buffer size
-
-	err := p.EncodeInto(&buf)
-	if err == nil {
-		t.Errorf("Expected error when buffer is too small")
 	}
 }
 
@@ -155,24 +136,26 @@ func TestEncodeIntoHandlesLargerBuffer(t *testing.T) {
 		command_status:  0,
 		sequence_number: 12345,
 	}
-	buf := make([]uint8, 20)
+	buf := bytes.NewBuffer(make([]byte, 20)) // larger buffer size
-	err := p.EncodeInto(&buf)
+	buf.Reset()
+	err := p.Encode(buf)
 
 	if err != nil {
 		t.Errorf("Expected no error, got %v", err)
 	}
 
-	if binary.BigEndian.Uint32(buf[0:4]) != p.command_length {
+	innerbuf := buf.Bytes()
-		t.Errorf("Expected command_length %d, got %d", p.command_length, binary.BigEndian.Uint32(buf[0:4]))
+	if binary.BigEndian.Uint32(innerbuf[0:4]) != p.command_length {
+		t.Errorf("Expected command_length %d, got %d", p.command_length, binary.BigEndian.Uint32(innerbuf[0:4]))
 	}
-	if binary.BigEndian.Uint32(buf[4:8]) != p.command_id {
+	if binary.BigEndian.Uint32(innerbuf[4:8]) != p.command_id {
-		t.Errorf("Expected command_id %d, got %d", p.command_id, binary.BigEndian.Uint32(buf[4:8]))
+		t.Errorf("Expected command_id %d, got %d", p.command_id, binary.BigEndian.Uint32(innerbuf[4:8]))
 	}
-	if binary.BigEndian.Uint32(buf[8:12]) != p.command_status {
+	if binary.BigEndian.Uint32(innerbuf[8:12]) != p.command_status {
-		t.Errorf("Expected command_status %d, got %d", p.command_status, binary.BigEndian.Uint32(buf[8:12]))
+		t.Errorf("Expected command_status %d, got %d", p.command_status, binary.BigEndian.Uint32(innerbuf[8:12]))
 	}
-	if binary.BigEndian.Uint32(buf[12:16]) != p.sequence_number {
+	if binary.BigEndian.Uint32(innerbuf[12:16]) != p.sequence_number {
-		t.Errorf("Expected sequence_number %d, got %d", p.sequence_number, binary.BigEndian.Uint32(buf[12:16]))
+		t.Errorf("Expected sequence_number %d, got %d", p.sequence_number, binary.BigEndian.Uint32(innerbuf[12:16]))
 	}
 }
 
@@ -183,24 +166,26 @@ func TestEncodeIntoUsesBigEndianEncoding(t *testing.T) {
 		command_status:  0,
 		sequence_number: 12345,
 	}
-	buf := make([]uint8, 16)
+	buf := bytes.NewBuffer(make([]byte, 16))
-	err := p.EncodeInto(&buf)
+	buf.Reset()
+	err := p.Encode(buf)
 
 	if err != nil {
 		t.Errorf("Expected no error, got %v", err)
 	}
 
-	if binary.BigEndian.Uint32(buf[0:4]) != p.command_length {
+	innerbuf := buf.Bytes()
-		t.Errorf("Expected command_length %d, got %d", p.command_length, binary.BigEndian.Uint32(buf[0:4]))
+	if binary.BigEndian.Uint32(innerbuf[0:4]) != p.command_length {
+		t.Errorf("Expected command_length %d, got %d", p.command_length, binary.BigEndian.Uint32(innerbuf[0:4]))
 	}
-	if binary.BigEndian.Uint32(buf[4:8]) != p.command_id {
+	if binary.BigEndian.Uint32(innerbuf[4:8]) != p.command_id {
-		t.Errorf("Expected command_id %d, got %d", p.command_id, binary.BigEndian.Uint32(buf[4:8]))
+		t.Errorf("Expected command_id %d, got %d", p.command_id, binary.BigEndian.Uint32(innerbuf[4:8]))
 	}
-	if binary.BigEndian.Uint32(buf[8:12]) != p.command_status {
+	if binary.BigEndian.Uint32(innerbuf[8:12]) != p.command_status {
-		t.Errorf("Expected command_status %d, got %d", p.command_status, binary.BigEndian.Uint32(buf[8:12]))
+		t.Errorf("Expected command_status %d, got %d", p.command_status, binary.BigEndian.Uint32(innerbuf[8:12]))
 	}
-	if binary.BigEndian.Uint32(buf[12:16]) != p.sequence_number {
+	if binary.BigEndian.Uint32(innerbuf[12:16]) != p.sequence_number {
-		t.Errorf("Expected sequence_number %d, got %d", p.sequence_number, binary.BigEndian.Uint32(buf[12:16]))
+		t.Errorf("Expected sequence_number %d, got %d", p.sequence_number, binary.BigEndian.Uint32(innerbuf[12:16]))
 	}
 }
 
@@ -211,28 +196,30 @@ func TestEncodeIntoConcurrencySafety(t *testing.T) {
 		command_status:  0,
 		sequence_number: 12345,
 	}
-	buf := make([]uint8, 16)
+	buf := bytes.NewBuffer(make([]byte, 16))
+	buf.Reset()
 	var wg sync.WaitGroup
 	for i := 0; i < 1000; i++ {
 		wg.Add(1)
 		go func() {
 			defer wg.Done()
-			p.EncodeInto(&buf)
+			p.Encode(buf)
 		}()
 	}
 	wg.Wait()
 
-	if binary.BigEndian.Uint32(buf[0:4]) != p.command_length {
+	innerbuf := buf.Bytes()
-		t.Errorf("Expected command_length %d, got %d", p.command_length, binary.BigEndian.Uint32(buf[0:4]))
+	if binary.BigEndian.Uint32(innerbuf[0:4]) != p.command_length {
+		t.Errorf("Expected command_length %d, got %d", p.command_length, binary.BigEndian.Uint32(innerbuf[0:4]))
 	}
-	if binary.BigEndian.Uint32(buf[4:8]) != p.command_id {
+	if binary.BigEndian.Uint32(innerbuf[4:8]) != p.command_id {
-		t.Errorf("Expected command_id %d, got %d", p.command_id, binary.BigEndian.Uint32(buf[4:8]))
+		t.Errorf("Expected command_id %d, got %d", p.command_id, binary.BigEndian.Uint32(innerbuf[4:8]))
 	}
-	if binary.BigEndian.Uint32(buf[8:12]) != p.command_status {
+	if binary.BigEndian.Uint32(innerbuf[8:12]) != p.command_status {
-		t.Errorf("Expected command_status %d, got %d", p.command_status, binary.BigEndian.Uint32(buf[8:12]))
+		t.Errorf("Expected command_status %d, got %d", p.command_status, binary.BigEndian.Uint32(innerbuf[8:12]))
 	}
-	if binary.BigEndian.Uint32(buf[12:16]) != p.sequence_number {
+	if binary.BigEndian.Uint32(innerbuf[12:16]) != p.sequence_number {
-		t.Errorf("Expected sequence_number %d, got %d", p.sequence_number, binary.BigEndian.Uint32(buf[12:16]))
+		t.Errorf("Expected sequence_number %d, got %d", p.sequence_number, binary.BigEndian.Uint32(innerbuf[12:16]))
 	}
 }
 
@@ -243,24 +230,26 @@ func TestEncodeIntoWithMaximumValues(t *testing.T) {
 		command_status:  math.MaxUint32,
 		sequence_number: math.MaxUint32,
 	}
-	buf := make([]uint8, 16)
+	buf := bytes.NewBuffer(make([]byte, 16))
-	err := p.EncodeInto(&buf)
+	buf.Reset()
+	err := p.Encode(buf)
 
 	if err != nil {
 		t.Errorf("Expected no error, got %v", err)
 	}
 
-	if binary.BigEndian.Uint32(buf[0:4]) != p.command_length {
+	innerbuf := buf.Bytes()
-		t.Errorf("Expected command_length %d, got %d", p.command_length, binary.BigEndian.Uint32(buf[0:4]))
+	if binary.BigEndian.Uint32(innerbuf[0:4]) != p.command_length {
+		t.Errorf("Expected command_length %d, got %d", p.command_length, binary.BigEndian.Uint32(innerbuf[0:4]))
 	}
-	if binary.BigEndian.Uint32(buf[4:8]) != p.command_id {
+	if binary.BigEndian.Uint32(innerbuf[4:8]) != p.command_id {
-		t.Errorf("Expected command_id %d, got %d", p.command_id, binary.BigEndian.Uint32(buf[4:8]))
+		t.Errorf("Expected command_id %d, got %d", p.command_id, binary.BigEndian.Uint32(innerbuf[4:8]))
 	}
-	if binary.BigEndian.Uint32(buf[8:12]) != p.command_status {
+	if binary.BigEndian.Uint32(innerbuf[8:12]) != p.command_status {
-		t.Errorf("Expected command_status %d, got %d", p.command_status, binary.BigEndian.Uint32(buf[8:12]))
+		t.Errorf("Expected command_status %d, got %d", p.command_status, binary.BigEndian.Uint32(innerbuf[8:12]))
 	}
-	if binary.BigEndian.Uint32(buf[12:16]) != p.sequence_number {
+	if binary.BigEndian.Uint32(innerbuf[12:16]) != p.sequence_number {
-		t.Errorf("Expected sequence_number %d, got %d", p.sequence_number, binary.BigEndian.Uint32(buf[12:16]))
+		t.Errorf("Expected sequence_number %d, got %d", p.sequence_number, binary.BigEndian.Uint32(innerbuf[12:16]))
 	}
 }
 
@@ -271,38 +260,39 @@ func TestEncodeIntoWithBoundaryValues(t *testing.T) {
 		command_status:  0,
 		sequence_number: 0,
 	}
-	buf := make([]uint8, 16)
+	buf := bytes.NewBuffer(make([]byte, 16))
-	err := p.EncodeInto(&buf)
+	buf.Reset()
+	err := p.Encode(buf)
 
 	if err != nil {
 		t.Errorf("Expected no error, got %v", err)
 	}
 
-	if binary.BigEndian.Uint32(buf[0:4]) != p.command_length {
+	innerbuf := buf.Bytes()
-		t.Errorf("Expected command_length %d, got %d", p.command_length, binary.BigEndian.Uint32(buf[0:4]))
+	if binary.BigEndian.Uint32(innerbuf[0:4]) != p.command_length {
+		t.Errorf("Expected command_length %d, got %d", p.command_length, binary.BigEndian.Uint32(innerbuf[0:4]))
 	}
-	if binary.BigEndian.Uint32(buf[4:8]) != p.command_id {
+	if binary.BigEndian.Uint32(innerbuf[4:8]) != p.command_id {
-		t.Errorf("Expected command_id %d, got %d", p.command_id, binary.BigEndian.Uint32(buf[4:8]))
+		t.Errorf("Expected command_id %d, got %d", p.command_id, binary.BigEndian.Uint32(innerbuf[4:8]))
 	}
-	if binary.BigEndian.Uint32(buf[8:12]) != p.command_status {
+	if binary.BigEndian.Uint32(innerbuf[8:12]) != p.command_status {
-		t.Errorf("Expected command_status %d, got %d", p.command_status, binary.BigEndian.Uint32(buf[8:12]))
+		t.Errorf("Expected command_status %d, got %d", p.command_status, binary.BigEndian.Uint32(innerbuf[8:12]))
 	}
-	if binary.BigEndian.Uint32(buf[12:16]) != p.sequence_number {
+	if binary.BigEndian.Uint32(innerbuf[12:16]) != p.sequence_number {
-		t.Errorf("Expected sequence_number %d, got %d", p.sequence_number, binary.BigEndian.Uint32(buf[12:16]))
+		t.Errorf("Expected sequence_number %d, got %d", p.sequence_number, binary.BigEndian.Uint32(innerbuf[12:16]))
 	}
 }
 
-
 // region decode
 func TestDecodeHandlesShortByteSlice(t *testing.T) {
 	var p PDU_HEADER
-	data := []uint8{0, 0, 0, 10}
+	data := []byte{0, 0, 0, 10}
 	defer func() {
 		if r := recover(); r != nil {
 			t.Errorf("Decode panicked with short byte slice")
 		}
 	}()
-	err := p.Decode(data)
+	err := p.Decode(bytes.NewBuffer(data))
 	if err != nil {
 		t.Errorf("Expected no error, got %v", err)
 	}
@@ -310,8 +300,8 @@ func TestDecodeHandlesShortByteSlice(t *testing.T) {
 
 func TestDecodeParsesValidByteSlice(t *testing.T) {
 	var p PDU_HEADER
-	data := []uint8{0, 0, 0, 16, 0, 0, 0, 1, 0, 0, 0, 2, 0, 0, 0, 3}
+	data := []byte{0, 0, 0, 16, 0, 0, 0, 1, 0, 0, 0, 2, 0, 0, 0, 3}
-	err := p.Decode(data)
+	err := p.Decode(bytes.NewBuffer(data))
 
 	if err != nil {
 		t.Errorf("Expected no error, got %v", err)
@@ -333,13 +323,13 @@ func TestDecodeParsesValidByteSlice(t *testing.T) {
 
 func TestDecodeHandlesLongerByteSliceWithoutCrashing(t *testing.T) {
 	var p PDU_HEADER
-	data := make([]uint8, 20)
+	data := make([]byte, 20)
 	defer func() {
 		if r := recover(); r != nil {
 			t.Errorf("Decode panicked with long byte slice")
 		}
 	}()
-	err := p.Decode(data)
+	err := p.Decode(bytes.NewBuffer(data))
 	if err != nil {
 		t.Errorf("Expected no error, got %v", err)
 	}
@@ -349,8 +339,8 @@ func TestDecodeHandlesNilDataInput(t *testing.T) {
 	var p PDU_HEADER
 	err := p.Decode(nil)
 
-	if err != nil {
+	if err == nil {
-		t.Errorf("Expected no error, got %v", err)
+		t.Errorf("Expected error, got none")
 	}
 
 	if p.command_length != 0 {
@@ -369,8 +359,8 @@ func TestDecodeHandlesNilDataInput(t *testing.T) {
 
 func TestDecodeHandlesEmptyByteSliceGracefully(t *testing.T) {
 	var p PDU_HEADER
-	data := []uint8{}
+	data := []byte{}
-	err := p.Decode(data)
+	err := p.Decode(bytes.NewBuffer(data))
 
 	if err != nil {
 		t.Errorf("Expected no error, got %v", err)
@@ -392,11 +382,11 @@ func TestDecodeHandlesEmptyByteSliceGracefully(t *testing.T) {
 
 func TestDecodeDoesNotModifyInputByteSlice(t *testing.T) {
 	var p PDU_HEADER
-	data := []uint8{0, 0, 0, 16, 0, 0, 0, 1, 0, 0, 0, 2, 0, 0, 0, 3}
+	data := []byte{0, 0, 0, 16, 0, 0, 0, 1, 0, 0, 0, 2, 0, 0, 0, 3}
-	originalData := make([]uint8, len(data))
+	originalData := make([]byte, len(data))
 	copy(originalData, data)
 
-	err := p.Decode(data)
+	err := p.Decode(bytes.NewBuffer(data))
 
 	if err != nil {
 		t.Errorf("Expected no error, got %v", err)
@@ -411,8 +401,8 @@ func TestDecodeDoesNotModifyInputByteSlice(t *testing.T) {
 
 func TestDecodeHandlesByteSlicesWithMaxUint32Values(t *testing.T) {
 	var p PDU_HEADER
-	data := []uint8{255, 255, 255, 255, 255, 255, 255, 255}
+	data := []byte{255, 255, 255, 255, 255, 255, 255, 255}
-	err := p.Decode(data)
+	err := p.Decode(bytes.NewBuffer(data))
 
 	if err != nil {
 		t.Errorf("Expected no error, got %v", err)
@@ -428,8 +418,8 @@ func TestDecodeHandlesByteSlicesWithMaxUint32Values(t *testing.T) {
 
 func TestDecodeHandlesByteSlicesWithMinimumUint32Values(t *testing.T) {
 	var p PDU_HEADER
-	data := []uint8{0, 0, 0, 0, 0, 0, 0, 0}
+	data := []byte{0, 0, 0, 0, 0, 0, 0, 0}
-	err := p.Decode(data)
+	err := p.Decode(bytes.NewBuffer(data))
 
 	if err != nil {
 		t.Errorf("Expected no error, got %v", err)
@@ -452,9 +442,8 @@ func TestSizeReturns16(t *testing.T) {
 }
 
 // region benchmarks
-
 // With buffer pool
-func BenchmarkEncode(b *testing.B) {
+func BenchmarkEncodeWithBufferPool(b *testing.B) {
 	p := &PDU_HEADER{
 		command_length:  16,
 		command_id:      1,
@@ -463,12 +452,14 @@ func BenchmarkEncode(b *testing.B) {
 	}
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
-		p.Encode()
+		buf := ByteBufferPool.Get(p.Size())
+		p.Encode(buf)
+		ByteBufferPool.Put(buf)
 	}
 }
 
 // Without buffer pool
-func BenchmarkEncodeInto(b *testing.B) {
+func BenchmarkEncodeWithoutBufferPool(b *testing.B) {
 	p := &PDU_HEADER{
 		command_length:  16,
 		command_id:      1,
@@ -477,16 +468,19 @@ func BenchmarkEncodeInto(b *testing.B) {
 	}
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
-		buf := make([]uint8, 16)
+		buf := bytes.Buffer{}
-		p.EncodeInto(&buf)
+		p.Encode(&buf)
 	}
 }
 
-func BenchmarkDecode(b *testing.B) {
+func BenchmarkDecodeBufferPool(b *testing.B) {
 	p := &PDU_HEADER{}
-	data := []uint8{0, 0, 0, 16, 0, 0, 0, 1, 0, 0, 0, 2, 0, 0, 0, 3}
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
-		p.Decode(data)
+		data := []byte{0, 0, 0, 16, 0, 0, 0, 1, 0, 0, 0, 2, 0, 0, 0, 3}
+		buf := ByteBufferPool.Get(len(data))
+		buf.Write(data)
+		p.Decode(buf)
+		ByteBufferPool.Put(buf)
 	}
-}
+}

pdu/submit.go

@@ -1,104 +1,162 @@
 package pdu
 
-import "fmt"
+import (
+	"bytes"
+	"encoding/ascii85"
+	"encoding/binary"
+	"fmt"
+	"log"
+
+	"github.com/warthog618/sms/encoding/gsm7"
+)
 
 type (
 	SUBMIT_SM struct {
-		header                 PDU_HEADER
+		header                 *PDU_HEADER
 		service_type           string
-		source_addr_ton        uint8
+		source_addr_ton        byte
-		source_addr_npi        uint8
+		source_addr_npi        byte
 		source_addr            string
-		dest_addr_ton          uint8
+		dest_addr_ton          byte
-		dest_addr_npi          uint8
+		dest_addr_npi          byte
 		destination_addr       string
-		esm_class              uint8
+		esm_class              byte
-		protocol_id            uint8
+		protocol_id            byte
-		priority_flag          uint8
+		priority_flag          byte
 		schedule_delivery_time string
 		validity_period        string
-		registered_delivery    uint8
+		registered_delivery    byte
-		replace_if_present     uint8
+		replace_if_present     byte
-		data_coding            uint8
+		data_coding            byte
-		sm_default_msg_id      uint8
+		sm_default_msg_id      byte
-		sm_length              uint8
+		sm_length              byte
 		short_message          string
 		// user_message_reference uint16
 		// source_port               uint16
-		// source_addr_subunit       uint8
+		// source_addr_subunit       byte
 		// destination_port          uint16
-		// dest_addr_subunit         uint8
+		// dest_addr_subunit         byte
 		// sar_msg_ref_num           uint16
-		// sar_total_segments        uint8
+		// sar_total_segments        byte
-		// sar_segment_seqnum        uint8
+		// sar_segment_seqnum        byte
-		// more_messages_to_send     uint8
+		// more_messages_to_send     byte
-		// payload_type              uint8
+		// payload_type              byte
 		// message_payload           string
-		// privacy_indicator         uint8
+		// privacy_indicator         byte
 		// callback_num              string
-		// callback_num_pres         uint8
+		// callback_num_pres         byte
 		// callback_num_atag         string
 		// source_subaddress         string
 		// dest_subaddress           string
-		// user_response_code        uint8
+		// user_response_code        byte
-		// display_time              uint8
+		// display_time              byte
-		// sms_signal                uint8
+		// sms_signal                byte
-		// ms_validity               uint8
+		// ms_validity               byte
-		// ms_msg_wait_facilities    uint8
+		// ms_msg_wait_facilities    byte
-		// number_of_messages        uint8
+		// number_of_messages        byte
-		// alert_on_message_delivery uint8
+		// alert_on_message_delivery byte
-		// language_indicator        uint8
+		// language_indicator        byte
-		// its_reply_type            uint8
+		// its_reply_type            byte
-		// its_session_info          uint8
+		// its_session_info          byte
-		// ussd_service_op           uint8
+		// ussd_service_op           byte
 	}
 	SUBMIT_SM_RESP struct {
-		header     PDU_HEADER
+		header     *PDU_HEADER
 		message_id string
 	}
 	SUBMIT_MULTI      struct{}
 	SUBMIT_MULTI_RESP struct{}
 )
 
-func (p *SUBMIT_SM) Encode() (*[]byte, error) {
+func (p *SUBMIT_SM) Encode(buf *bytes.Buffer) error {
-	buf := ByteBufferPool.Get(uint(p.Size()))
-	err := p.EncodeInto(buf)
-	return buf, err
-}
-func (p *SUBMIT_SM) EncodeInto(buf *[]byte) error {
 	if buf == nil {
-		return fmt.Errorf("cannot encode SUBMIT_SM, buffer is nil")
+		return fmt.Errorf("cannot encode into nil buffer")
 	}
-	if len(*buf) < int(p.Size()) {
+	// This won't do...
-		return fmt.Errorf("cannot encode SUBMIT_SM, buffer too small (%d, required %d)", len(*buf), p.Size())
+	// TODO: Implement your own encoders and shit
+	// ASCII is easy
+	// UCS2 should also be fairly easy, use uint16 or something
+	// GSM7 will not be easy
+	// See https://www.codeproject.com/Tips/470755/Encoding-Decoding-7-bit-User-Data-for-SMS-PDU-PDU
+	asciiEncoder := ascii85.NewEncoder(buf)
+	// TODO: Implement encodings bsed on p.data_coding
+	messageEncoder := gsm7.NewEncoder()
+
+	p.header.Encode(buf)
+	n, err := asciiEncoder.Write([]byte("OOO"))
+	if err != nil {
+		return err
 	}
-
+	log.Println(n)
-	p.header.EncodeInto(buf)
+	// asciiEncoder.Write([]byte(p.service_type))
-
+	buf.Write(NULL_ARR)
+	binary.Write(buf, binary.BigEndian, p.source_addr_ton)
+	binary.Write(buf, binary.BigEndian, p.source_addr_npi)
+	asciiEncoder.Write([]byte(p.source_addr))
+	buf.Write(NULL_ARR)
+	binary.Write(buf, binary.BigEndian, p.dest_addr_ton)
+	binary.Write(buf, binary.BigEndian, p.dest_addr_npi)
+	asciiEncoder.Write([]byte(p.destination_addr))
+	buf.Write(NULL_ARR)
+	binary.Write(buf, binary.BigEndian, p.esm_class)
+	binary.Write(buf, binary.BigEndian, p.protocol_id)
+	binary.Write(buf, binary.BigEndian, p.priority_flag)
+	asciiEncoder.Write([]byte(p.schedule_delivery_time))
+	buf.Write(NULL_ARR)
+	asciiEncoder.Write([]byte(p.validity_period))
+	buf.Write(NULL_ARR)
+	binary.Write(buf, binary.BigEndian, p.registered_delivery)
+	binary.Write(buf, binary.BigEndian, p.replace_if_present)
+	binary.Write(buf, binary.BigEndian, p.data_coding)
+	binary.Write(buf, binary.BigEndian, p.sm_default_msg_id)
+	binary.Write(buf, binary.BigEndian, p.sm_length)
+	encodedMsg, err := messageEncoder.Encode([]byte(p.short_message))
+	if err != nil {
+		return err
+	}
+	buf.Write(encodedMsg)
 	return nil
 }
-func (p *SUBMIT_SM) Decode(data []byte) {
+func (p *SUBMIT_SM) Decode(buf *bytes.Buffer) error {
+	if buf == nil {
+		return fmt.Errorf("cannot decode nil buffer")
+	}
+	return nil
 }
-func (p *SUBMIT_SM) Size() uint32 {
+func (p *SUBMIT_SM) Size() int {
-	var size uint32
+	var size int
 	size += p.header.Size()
-	size += uint32(len(p.service_type) * 1)
+	size += 1 + len(p.service_type)
 	size += 1 // source_addr_ton
 	size += 1 // source_addr_npi
-	size += uint32(len(p.source_addr) * 1)
+	size += 1 + len(p.source_addr)
 	size += 1 // dest_addr_ton
 	size += 1 // dest_addr_npi
-	size += uint32(len(p.destination_addr) * 1)
+	size += 1 + len(p.destination_addr)
 	size += 1 // esm_class
 	size += 1 // protocol_id
 	size += 1 // priority_flag
-	size += uint32(len(p.schedule_delivery_time) * 1)
+	size += 1 + len(p.schedule_delivery_time)
-	size += uint32(len(p.validity_period) * 1)
+	size += 1 + len(p.validity_period)
 	size += 1 // registered_delivery
 	size += 1 // replace_if_present
 	size += 1 // data_coding
 	size += 1 // sm_default_msg_id
 	size += 1 // sm_length
-	size += uint32(len(p.short_message) * 1)
+	// TODO: Handle encoding based on p.data_coding
+	switch p.data_coding {
+	case 0b00000000: // GSM7
+		size += (len(p.short_message)*7 + 8 - 1) / 8
+	case 0b00000001: // ASCII
+		size += len(p.short_message)
+	case 0b00000011: // LATIN1
+		size += len(p.short_message)
+	case 0b00001000: // UCS2
+		size += len(p.short_message) * 2
+	}
 	return size
 }
+func (p *SUBMIT_SM) UpdateSize() {
+	p.header.command_length = uint32(p.Size())
+	p.sm_length = byte(len(p.short_message))
+}

pdu/submit_test.go

@@ -1,9 +1,72 @@
 package pdu
 
 import (
+	"bytes"
 	"testing"
 )
 
+// region encode
+// See examples: https://www.openmarket.com/docs/Content/apis/v4smpp/mt-examples.htm
+func TestEncodeFunctionCorrectlyEncodesAllFields(t *testing.T) {
+	p := &SUBMIT_SM{
+		header: &PDU_HEADER{
+			command_length:  0,
+			command_id:      4,
+			command_status:  0,
+			sequence_number: 378019,
+		},
+		service_type:           "OMV4",
+		source_addr_ton:        3,
+		source_addr_npi:        1,
+		source_addr:            "80362",
+		dest_addr_ton:          1,
+		dest_addr_npi:          1,
+		destination_addr:       "812345001000",
+		esm_class:              0,
+		protocol_id:            0,
+		priority_flag:          0,
+		schedule_delivery_time: "",
+		validity_period:        "180105120000004+",
+		registered_delivery:    1,
+		data_coding:            1, // The example uses 0 and claims to use GSM but the message is encoded as ASCII...
+		sm_default_msg_id:      0,
+		short_message:          "Reply Yes to opt in or No to opt out.",
+	}
+	p.UpdateSize()
+	buf := ByteBufferPool.Get(p.Size())
+	err := p.Encode(buf)
+	if err != nil {
+		t.Fatalf("expected no error, got %v", err)
+	}
+
+	expected := []byte{0,0,0,107,0,0,0,4,0,0,0,0,0,5,196,163,79,77,86,52,0,3,1,56,48,51,54,50,0,1,1,56,49,50,51,52,53,48,48,49,48,48,48,0,0,0,0,0,49,56,48,49,48,53,49,50,48,48,48,48,48,48,52,43,0,1,0,0,0,37,82,101,112,108,121,32,89,101,115,32,116,111,32,111,112,116,32,105,110,32,111,114,32,78,111,32,116,111,32,111,112,116,32,111,117,116,46}
+	if !bytes.Equal(buf.Bytes(), expected) {
+		t.Fatalf("expected %v, got %v", expected, buf.Bytes())
+	}
+}
+
+// func TestRealScenario(t *testing.T) {
+//
+// 	p.header.command_length = uint32(p.Size())
+// 	p.sm_length = byte(len(p.short_message))
+// 	buf := make([]byte, p.Size())
+// 	err := p.EncodeInto(&buf)
+// 	if err != nil {
+// 		t.Errorf("Expected no error, got %v", err)
+// 	}
+// 	if len(buf) != len(expected) {
+// 		t.Errorf("Expected byte slice of length %d, got %d", len(expected), len(buf))
+// 	}
+// 	for i, v := range buf {
+// 		if v != expected[i] {
+// 			t.Errorf("Expected byte slice with values %v, got %v", expected, buf)
+// 			break
+// 		}
+// 	}
+// }
+
+// region decode
+
 // region size
 func TestCalculateSizeTypicalInstance(t *testing.T) {
 	p := &SUBMIT_SM{
@@ -14,7 +77,7 @@ func TestCalculateSizeTypicalInstance(t *testing.T) {
 		validity_period:        "",
 		short_message:          "Hello, World!",
 	}
-	expectedSize := uint32(16 + len(p.service_type) + 1 + 1 + len(p.source_addr) + 1 + 1 + len(p.destination_addr) + 1 + 1 + 1 + len(p.schedule_delivery_time) + len(p.validity_period) + 1 + 1 + 1 + 1 + 1 + len(p.short_message))
+	expectedSize := 16 + len(p.service_type) + 1 + 1 + len(p.source_addr) + 1 + 1 + len(p.destination_addr) + 1 + 1 + 1 + len(p.schedule_delivery_time) + len(p.validity_period) + 1 + 1 + 1 + 1 + 1 + len(p.short_message)
 	actualSize := p.Size()
 	if actualSize != expectedSize {
 		t.Errorf("Expected size %d, but got %d", expectedSize, actualSize)
@@ -31,7 +94,7 @@ func TestCalculateSizeMaxLengths(t *testing.T) {
 		validity_period:        string(make([]byte, maxLen)),
 		short_message:          string(make([]byte, maxLen)),
 	}
-	expectedSize := uint32(16 + maxLen + 1 + 1 + maxLen + 1 + 1 + maxLen + 1 + 1 + 1 + maxLen + maxLen + 1 + 1 + 1 + 1 + 1 + maxLen)
+	expectedSize := 16 + maxLen + 1 + 1 + maxLen + 1 + 1 + maxLen + 1 + 1 + 1 + maxLen + maxLen + 1 + 1 + 1 + 1 + 1 + maxLen
 	actualSize := p.Size()
 	if actualSize != expectedSize {
 		t.Errorf("Expected size %d, but got %d", expectedSize, actualSize)
@@ -47,9 +110,11 @@ func TestHandlesEmptyStringsForAllStringFields(t *testing.T) {
 		validity_period:        "",
 		short_message:          "",
 	}
-	expectedSize := uint32(16 + len(p.service_type) + 1 + 1 + len(p.source_addr) + 1 + 1 + len(p.destination_addr) + 1 + 1 + 1 + len(p.schedule_delivery_time) + len(p.validity_period) + 1 + 1 + 1 + 1 + 1 + len(p.short_message))
+	expectedSize := 16 + len(p.service_type) + 1 + 1 + len(p.source_addr) + 1 + 1 + len(p.destination_addr) + 1 + 1 + 1 + len(p.schedule_delivery_time) + len(p.validity_period) + 1 + 1 + 1 + 1 + 1 + len(p.short_message)
 	actualSize := p.Size()
 	if actualSize != expectedSize {
 		t.Errorf("Expected size %d, but got %d", expectedSize, actualSize)
 	}
 }
+
+// region benchmark